Weight of these is 10-12kg according to Tarmac in a post from a couple of years back.
However as pointed out these are not going to be of the highest quality nor of the lowest weight: You can expect them to look good for a bit but then I'd expect the finish to come off and the extra weight to be noticeable. However they're a brand new set of 19" wheels for £500, which is pretty much an absolute bargain if you like the looks Not everyone can afford or wants to spend £1500 on a set of wheels, certainly I bought cheap-ass Japan Racing wheels for my old BMW and they did the job for me perfectly, as well as being lighter than the heavy OEM ones